Northern Lite - the good the bad and the ugly.

What about Bigfoot? I would also take a look at Cirrus and if a inside shower isn't a necessity Alaskan makes a very dependable TC.

"(Very large name brand in the TC world, purchased new 2015)"

I wouldn't say the name either. Keep it a secret! Let us guess. Since they are VERY large! Yes, I have lots of advice but will keep it secret.

To be honest, if you want a camper that will last 20 years you have two options. Buy something from about 1996 - 2005ish, do a little maintenance and then take care of it. Or, buy a new camper of any brand, remove all the windows and reseal, remove all the corner trim and reseal, remove any roof penetration and reseal, then keep up with the maintenance. They have just started making them with so many corners cut to reduce cost including quality of labor that nothing is well sealed today as you have already partly found out.

That said, if I wanted to buy new, go with a Bigfoot or Northernlite. However, I will continue to buy used with care even though I can afford new and replace each 10+ years as needed. I paid $5k for a used unit 8 years ago and it'll give me at least another 3 until I want to go a bit larger for full timing. And when I sell it, I'll probably get $5k for it with only a few hundred invested in minor repairs.

I've got one. A 2011 model. I've owned several different types of rvs but only two different types of truck campers. A Lance and now my Northern Lite.
Appliances are a wash, they all seem to use similar appliances so there is nothing to discuss there.
So now all that's left is how its built. I know all about the maintenance required with corner moulding and rubber roofs and things like that. The Northern Lite has none of that so that's a really good thing. Less maintenance. Everybody wants that right? But lets be real here. Sure the fiberglass shell they build it pretty much water proof, right up until you cut a bunch of holes into it. Of course the holes are needed for things like windows, vents, appliances, etc, etc, etc.
Not so waterproof anymore. On mine, three out of five windows leaked. And let me tell you, the Northern Lites hide the leaks well. It can leak in one corner and the water can travel a crazy distance to where you notice it. It takes some serious investigation to really find the leaks.
I took all my windows out early this year and resealed them. No more leaking there. I know others that have had other leaks as well. So are they perfect? Of course not. No RV is. But I think they are a very good way of building a nice camper.
Would I buy another, absolutely.

So you had a Lance?